biodiverseed:

PLANTING MISTLETOE

For over a decade, European Mistletoe (Viscum album) has been intentionally planted on several of the crabapple trees at the farm. It looks absolutely gorgeous in the winter.

This hemiparasitic plant is normally spread by birds (zoochory). Some mistletoe-feeders have specialised digestive tracks that allow them to break down the viscin (adhesive cellulosic strands and mucopolysaccharides contained in the sticky fruit pulp), and they pass the undigested seeds onto a branch, gluing them in place with guano. Other birds will find the drupe too sticky, and will wipe their beaks on the branch, depositing the seed and viscin (which hardens rapidly upon exposure to air) on the host plant.

After the seed germinates, it forms a root-like organs called haustoria. These penetrate the tissues of the host plant: stealing water, nutrients, and sugars, and the hemiparasite begins to dramatically reduce independent photosynthetic activity.

An aggressive mistletoe infestation can kill the branch or host plant, so the spread has to be controlled within reason. However, as mentioned, several of the trees on this property have hosted mistletoe for ten or more years, without issue.

Though seemingly a pointlessly destructive addition to a domestic garden, mistletoe is a keystone species: an important nesting site for a number of birds, and other organisms. It also has a rich ethnobotanical history here in Northern Europe.

In February (apparently the best time to attach them to trees) I’ll be getting a few seeds from these plants in the mail, and planting them on the apple trees we only use for flavouring liquor. Since we want to keep the harvest of these apple varieties small and manageable, it seems reasonable to add a beautiful and wildlife-attracting parasitic plant into the mix.

#mistletoe #botany #birds #malus (apples) #keystone species